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Varying concentration on surface of a sphere
Posted 10 juin 2015, 04:38 UTC−4 Chemical Reaction Engineering Version 4.3 2 Replies
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Hello,
I'm working in COMSOL 4.3a with the Transport of Diluted Species module. I have created a simple sphere and would like to model outward flux of a certain species given an external boundary condition (initial surface concentration). As a test to understand how COMSOL does its calculations, I want to make one half of the sphere have a different initial surface concentration than the other half.
Since the Transport of Diluted Species module cannot be set to evaluate on the boundary only, I am storing the concentration (c) defined in Initial Values in variables that are then used in equations also defined in the same Variables group. One variable simply multiplies c by 10 as a test to see if there is any difference in the final concentration. For both variable groups, Geometric Entity Level is set to the respective boundaries (i.e. each half of the sphere).
When I run the time-dependent study, the surface concentration ends up being uniform all the way around even though I tried to make one half of the sphere have a different initial surface concentration. Any suggestions would be helpful!
Thanks,
Sam
I'm working in COMSOL 4.3a with the Transport of Diluted Species module. I have created a simple sphere and would like to model outward flux of a certain species given an external boundary condition (initial surface concentration). As a test to understand how COMSOL does its calculations, I want to make one half of the sphere have a different initial surface concentration than the other half.
Since the Transport of Diluted Species module cannot be set to evaluate on the boundary only, I am storing the concentration (c) defined in Initial Values in variables that are then used in equations also defined in the same Variables group. One variable simply multiplies c by 10 as a test to see if there is any difference in the final concentration. For both variable groups, Geometric Entity Level is set to the respective boundaries (i.e. each half of the sphere).
When I run the time-dependent study, the surface concentration ends up being uniform all the way around even though I tried to make one half of the sphere have a different initial surface concentration. Any suggestions would be helpful!
Thanks,
Sam
2 Replies Last Post 10 juin 2015, 10:55 UTC−4
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Posted:
9 years ago
I made some progress by adding two Concentration boundary conditions under the Transport of Diluted Species module that I can define each half of the sphere with. This might be what I was looking for.
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Posted:
9 years ago
Well that wasn't it. Those boundary conditions just set the concentration on the surface to a specific value.